MAX66040 Maxim, MAX66040 Datasheet - Page 9

• Manufacturer Part Number: MAX66040
• Description: The MAX66040 combines 1024 bits of user EEPROM with secure hash algorithm (SHA-1) challenge-and-response authentication (ISO/IEC 10118-3 SHA-1), a 64-bit unique identifier (UID), one 64-bit secret, and a 13
• Manufacturer: Maxim

Figure 14. Bit Assignments for S-Block PCB
Figure 15. Bit Assignments for CID Byte in I-Blocks
Figure 16. Frame Format for Block Transmission Protocol
For S-blocks, the states of bit 1, bit 2, and bit 3, and bit 7
and bit 8 are fixed and must be transmitted as shown in
Figure 14. The function of bit 4 (CID indicator) is the
same as for I-blocks. Bit 5 and bit 6, when being 00b,
specify whether the S-block represents a deselect com-
mand. If bit 5 and bit 6 are 11b, the S-block represents a
frame-waiting time extension (WTX) request, a feature to
tell the master that the response is going to take longer
than specified by the frame-waiting time (FWT) (see the
ATQB Response section). However, the MAX66040 does
not use this feature and consequently, the only use of the
S-block is to transition the device from the ACTIVE state
to the HALT state using the DESELECT command (see
the Network Function Commands section).
Figure 15 shows the bit assignment within the card
identifier byte. The purpose of bits 4 to 1 is to select
one of multiple slave devices that the master has ele-
vated to the ACTIVE state. The CID is assigned to a
slave through Param 4 of the ATTRIB command (see
the Network Function Commands section). While in
ACTIVE state, a compliant slave only processes blocks
that contain a matching CID and blocks without CID if
the assigned CID is all zeros. If the master includes a
CID, then the slave’s response also includes a CID
byte. Blocks with a nonmatching CIDs are ignored.
SOF
(POWER LEVEL)
MSB
BIT 8
MSB
BIT 8
1
0
PCB
BIT 7
BIT 7
1
0
CID
BIT 6
BIT 6
INFORMATION FIELD
______________________________________________________________________________________
0
(FIXED)
BIT 5
BIT 5
0
ABRIDGED DATA SHEET
BIT 4
BIT 4
CID
CARD IDENTIFIER VALUE
CRC (LSB)
BIT 3
BIT 3
0
ISO/IEC 14443 Type B-Compliant
Card Identifier
CRC (MSB)
BIT 2
BIT 2
1
BIT 1
BIT 1
LSB
LSB
0
EOF
According to the standard, the slave can use bits 8 and
7 to inform the master whether power-level indication is
supported, and, if yes, whether sufficient power is avail-
able for full functionality. Since the MAX66040 does not
support power-level indication, the power-level bits are
always 00b. When the master transmits a CID byte, the
power-level bits must be 00b.
Since the MAX66040 does not generate WTX requests,
the information field (Figure 11) is found only with
I-blocks. The length of the information field is calculated
by counting the number of bytes of the whole block
minus length of prologue and epilogue field. The
ISO/IEC 14443 standard does not define any rules for
the contents of the information field. The MAX66040
assumes that the first byte it receives in the information
field is a command code followed by 0 or more com-
mand-specific parameters. When responding to an
I-block, the first byte of the information field indicates
success (code 00h) followed by command-specific
data or failure (code 01h) followed by one error code.
The commands described in this section are transmit-
ted using the block transmission protocol. The data of a
block (from prologue to epilogue) is embedded
between SOF and EOF, as shown in Figure 16. The CID
field (shaded) is optional. If the request contains a CID,
the response also contains a CID.
The command descriptions in this section only show
the information field of the I-blocks used to transmit
requests and responses. Since the MAX66040 neither
supports chaining nor generates WTX requests, when it
receives an I-block, the MAX66040 responds with an
I-block. The block number in the I-block response is the
same as in the I-block request.
Secure Memory
Memory and Control
Function Commands
Information Field
11